The Chi-squared distribution is a statistical distribution commonly used in hypothesis testing and confidence interval estimation. It is defined by its degrees of freedom, which typically correspond to the number of independent variables in a dataset. The distribution is positively skewed, meaning it has a longer tail on the right side. This distribution is particularly useful in tests like the Chi-squared test, which assesses how well observed data fit expected data. It helps researchers determine if there are significant differences between categorical variables, making it a vital tool in fields such as social sciences and biostatistics.